Vax, a game by Ellsworth Campbell and Isaac Bromley, explores how a disease spreads through a network, starting with just one infected person. It's a simple concept that works well.
When you start the game, you have a network of uninfected people. The more connected a person is, the more chances that person can infect others upon his or her own infection. Your goal is to strategically administer a limited supply of vaccinations and to quarantine people to prevent as many infections as you can.
Fun and educational. Woo.